Peerages for the Kingdom of Ireland

By title: O

All peerages for Kingdom of Ireland

Navigate via first letter of Title

Title Letters patent Extinct Merged into crown
O'Brien (Barony) Murrough O'Brien - Wed 21st Oct 1654 3 July 1855 -
of Offaly (Earldom) James Fitzgerald - Thu 19th Mar 1761 - -
Ogle (Viscountcy) William Ogle - Sat 23rd Dec 1645 14 July 1682 -
O'Grady (Barony) Standish O'Grady - Thu 6th Jan 1831 15 October 1955 -
O'Neill (Earldom) Charles Henry O'Neill - Thu 28th Aug 1800 25 March 1841 -
O'Neill (Viscountcy) John O'Neill - Sat 3rd Oct 1795 12 February 1855 -
O'Neill (Barony) John O'Neill - Fri 25th Oct 1793 12 February 1855 -
Ongley (Barony) Robert Henley Ongley - Tue 30th Jul 1776 21 January 1877 -
Oranmore and Browne (Barony) Dominick Browne - Wed 4th May 1836 - -
Oriel (Barony) Margaretta Amelia Foster - Sat 5th Jun 1790 - -
of Ormond (Dukedom) James Butler - Wed 30th Mar 1661 17 December 1758 -
of Ormond (Marquessate) James Butler - Sat 30th Aug 1642 17 December 1758 -
of Ormond (Marquessate) Walter Butler - Fri 12th Jan 1816 10 August 1820 -
of Ormond (Marquessate) James Wandesford Butler - Wed 5th Oct 1825 25 October 1997 -
of Orrery (Earldom) Roger Boyle - Sun 5th Sep 1660 - -
Orwell (Viscountcy) Francis Vernon - Sun 21st Jul 1776 15 October 1783 -
Orwell (Barony) Francis Vernon - Wed 7th Apr 1762 15 October 1783 -
of Ossory (Earldom) Piers Butler - Sun 23rd Feb 1528 - -
Oxmantown (Barony) Richard Parsons - Wed 2nd Jul 1681 27 August 1764 -
Oxmantown (Viscountcy) Laurence Harman Harman - Fri 2nd Oct 1795 20 April 1807 -